Instrumentation and computer capabilities that measure, record, display and duplicate preconsious jaw movements have been developed. This Replicator system provides a basis for objective study and evaluation of occlusion. A partial listing of parameters investigated includes paths of movement of the central incisor, condyles and molars; instantaneous centers of rotation; and velocity characteristics of jaw movements. A data base for adult subjects with good occlusion and specific malocclusion has been established and it is proposed to record young subjects in their growth and development period. These data enhance the basic understanding of the neuromuscular control and guidance of the jaw. An objective of this research is to provide specifications for restorative dentistry by categorizing condylar border movement pathways from two independent studies: 1) Replicator-electronic method and 2) Lee System--engraving method. Preliminary studies show that jaw movement analyzers and articulator controls used in fixed and removable prosthodontics would be greatly simplified. Patients in dysfunction, patients undergoing treatment and normal patients modified with the insertion of restorations with known occlusal interferences are being studied in relation to diagnosis of dysfunction and treatment evaluation. The recorded data will provide basic criteria for evaluation: 1) occlusal disharmonies; 2) TMJ disorders and 3) muscle dysfunction. These studies will lead to an improvement of dental treatment services as they relate to occlusion. BIBLIOGRAPHIC REFERENCES: Gibbs, C.H.: Electromyographic Activity during the Motionless Period of Chewing, Journal of Prosthetic Dentistry, Vol. 34, No. 1, pp. 34-40, July, 1975. Gibbs, C.H., Lauffer R., Lundeen, H.C., Shryock, E.F. and Wirth, C.G.: "A Computer Categorization and Evaluation of Human Jaw Movements". Proceedings of the 28th Annual Conference of the Alliance of Engineering in Medicine and Biology, p. 186, September, 1975.